Hydraulic pump

ABSTRACT

A hydraulic pump especially adapted for full power hydraulic braking systems wherein an eccentrically mounted rotor is adapted to reciprocate a shuttle block, the latter being provided with inlet and outlet openings and having a pumping chamber is which the rotor is mounted, rotational movement of the rotor effecting a pumping action of the fluid as well as controlling the inlet and outlet of fluid to and from the pumping chamber.

United States Patent lnventor Denis Connolly Fremont, Ohio Appl. No. 76,490 Filed Sept. 29, 1970 Patented Dec. 28, 1971 Assignee Bendix-Westinghouse Automotive Air Brake Company Elyria, Ohio HYDRAULIC PUMP 4 Claims, 3 Drawing Figs.

US. Cl. 417/466, 417/491, 417/493 Int. Cl ..F04b 29/00, F04b 19/02 Field of Search 417/466, 491, 492, 493, 494, 495

[56] References Cited UNITED STATES PATENTS 2,459,388 1/1949 Munroe et al. 417/466 2,504,945 4/1950 Austin et a1 417/466 X FORElGN PATENTS 1,260,047 3/1961 France 417/466 Primary Examiner-Carlton R. Croyle Assistant Examiner-Richard E. Gluck Attorney-Scrivener, Parker, Scrivener and Clarke ABSTRACT: A hydraulic pump especially adapted for full power hydraulic braking systems wherein an eccentrically mounted rotor is adapted to reciprocate a shuttle block, the latter being provided with inlet and outlet openings and having a pumping chamber is which the rotor is mounted, rotational movement of the rotor effecting a pumping action of the fluid as well as controlling the inlet and outlet of fluid to and from the pumping chamber.

11 nvhnmuuc PUMP DESCRIPTION OF THE INVENTION The present invention relates to a hydraulic pump of the eccentric rotor type which may be of extremely compact design but possessing maximum reliability and especially adapted for use in full power hydraulic braking systems.

The principal object of the invention resides in the provision of a novel pump structure having a rotatable eccentric for reciprocating a shuttle block, rotation of the eccentric not only effecting a pumping action but also serving to control the inlet and delivery ports of the pump during reciprocation of the shuttle block.

A further object is to provide a pump of the above character wherein the shuttle block contains a pumping chamber in which the eccentric rotor is mounted, the arrangement being such as to provide two pumping strokes for each revolution of the rotor.

A still further object resides in the provision of an eccentric pump of compact size and having a minimum number of working parts, the arrangement being such as to be highly reliable in operation.

Other objects and novel features of the invention will appear more fully hereinafter from a consideration of the accompanying drawing wherein a preferred embodiment of the invention is illustrated.

Referring to the drawings, wherein similar reference characters are used to designate similar parts throughout the several views:

FIG. 1 is a transverse sectional view of a pump constructed in accordance with the principles of the present invention;

FIG. 2 is an axial view, partly in section of the pump of FIG. 1, and

FIG. 3 is a partial view in section of the pump of FIG. 1 and illustrating a midposition of the pump eccentric where both inlet ports are substantially closed.

A pump embodying the principles of the present invention is illustrated in FIG. 1 as being incorporated in a full power hydraulic braking system of the type including a reservoir 12 of hydraulic fluid connected by conduits 114 and 16 to the pump 10, the latter serving to supply an accumulator 18 with pressurized fluid through conduits 20 and 22 having suitable check valves 24 and 26 therein.

As shown, pump 10 includes a casing 27 having top and bottom walls 28, 30 having respective aligned inlet ports 32, 34 therein for receiving hydraulic fluid from the reservoir 12 by way of conduits 14 and 16. The pump casing 27 also includes a pair of sidewalls 36 and 38 in which outlet ports 40 and 42 are respectively located, the ports 40 and 42 being positioned substantially midway between the walls 28 and 30 and being respectively connected with the conduits 22 and 20 leading to the accumulator 18. The walls 28, 30 and 36, 38 define a cavity 44 for receiving the novel pumping elements of the invention which will appear more fully hereinafter.

In the form of the invention herein illustrated, the novel pumping elements include a shuttle block 46 which is mounted for reciprocating movement within the cavity, such movement being effected by an eccentric rotor 48 drivably connected to a driving shaft 50, the latter being suitably journaled in end walls 52 and 54 as will appear from FIG. 2. The shuttle block 46 is provided with an elongated pumping cavity 56 in which the rotor 48 is positioned in such manner that the surface of the latter is in constant engagement with parallel upper and lower walls 58 and 60 and spaced from cylindrical end walls 62 and 64 to define oppositely disposed pressure chambers 66 and 68. As shown, the block 46 is provided with a pair of aligned inlet ports or openings 70 and 72 and is also provided with a pair of aligned outlet ports or openings 74 and 76, the arrangement being such that when the ports occupy the position shown in FIG. I, the inlet ports 32, 34 are aligned with openings 70 and 72 and the outlet ports 40, 42 are aligned with the openings 74 and 76.

In operation and with the pump 10 connected in the hydraulic system as shown in FIG. 1, it will be understood that the pressure chamber 68 is supplied with hydraulic fluid through 32, 70 and 34, 72. Clockwise rotation of the eccentric 48 through operation of the shaft 50, will cause reciprocation of the shuttle block 46 and as shown in FIG. 3, the initial movement of the eccentric 48 and block 46 will move the latter upwardly in the cavity 44 until the inlet openings 70 and 72 to the pumping cavity 56 are closed by the surface of the eccentric rotor 48. During such movement the outlet openings 74 and 76 are moved out of registry with the respective ports 40 and 42. Continued rotation of the rotor will thereupon move the block 46 downwardly and simultaneously pressurize the fluid within the pressure chamber 68 until the opening 76 begins to register with the port 42 at which time the pressurized fluid will flow to the accumulator 18 past check valve 24 and conduit 20. During such pressurizing of the fluid within the chamber 68 it will be noted that the rotor 48 uncovers the openings 70 and 72 so that the cavity 66 will then be charged with fluid from the cavity 44. At this time, the eccentric rotor 48 has moved through that is, a half revolution and the shuttle block 46 has made one complete excursion from the position shown in FIG. I.

In the continued rotation of the rotor 48, it will be readily understood that the block 46 will be moved downwardly as viewed in FIG. 1 to move the outlet openings 74 and 76 out of registry with respective ports 40 and 42. Thereafter, the rotor 48 will close communication between the ports 70, 72 and the pressure chamber 66 to be followed by the pressurization of the fluid within the chamber until the parts again assume the positions shown in FIG. 1 where the outlet 74 again registers with the outlet port 40 in order to conduct the pressurized fluid from the chamber 66 to the accumulator 18.

From the foregoing it will be readily seen that the present invention provides a relatively simple and inexpensive rotary pump wherein during operation, the eccentric rotor reciprocates a shuttle block for controlling the outlet ports from a pair of pressurizing chambers and wherein the rotor not only provides two working strokes per revolution but also controls the inlet ports to the respective pressurizing chambers.

While the invention has been described herein with considerable particularity the scope thereof is defined in the appended claims.

What is claimed is:

1. A rotary pump comprising a casing having an inlet port for hydraulic fluid and an outlet port for delivery of pressurized hydraulic fluid, said casing being provided with a cavity communicating with said delivery port, a shuttle block mounted for reciprocating movement in said cavity and provided with an elongated pumping chamber having an inlet opening aligned at all times with said inlet port and an outlet opening aligned with said outlet port when said block occupies a position intermediate the ends of said cavity, said chamber having upper and lower parallel sidewalls and cylindrical end walls, and means for pressurizing fluid within said chamber comprising an eccentric positioned in said chamber with the surface thereof contacting the sidewalls of said chamber, and means for rotating said eccentric to thereby reciprocate said shuttle block, said eccentric closing said inlet opening and thereafter pressurizing the fluid within the pumping chamber until said outlet opening is aligned with said outlet port.

2. A rotary pump as set forth in claim 1 wherein said casing has parallel top and bottom walls and a pair of parallel sidewalls, said inlet port being positioned in the top wall and the outlet port being positioned in one of the sidewalls, a second inlet port positioned in aligned relationship with the first named inlet port and located in said bottom wall, and a second outlet port positioned in the other sidewall and aligned with the first named outlet port, said pumping chamber having a second inlet opening aligned with the first named inlet opening and having a second outlet opening aligned with the first named outlet opening, rotation of said eccentric alternately is a minimum when the outlet opening registers with the outlet port.

4. A pump as set forth in claim 2 wherein the volumes between opposite ends of the pumping chamber and the eccentric are alternately at a minimum during reciprocation of said shuttle block in opposite directions.

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1. A rotary pump comprising a casing having an inlet port for hydraulic fluid and an outlet port for delivery of pressurized hydraulic fluid, said casing being provided with a cavity communicating with said delivery port, a shuttle block mounted for reciprocating movement in said cavity and provided with an elongated pumping chamber having an inlet opening aligned at all times with said inlet port and an outlet opening aligned with said outlet port when said block occupies a position intermediate the ends of said cavity, said chamber having upper and lower parallel sidewalls and cylindrical end walls, and meAns for pressurizing fluid within said chamber comprising an eccentric positioned in said chamber with the surface thereof contacting the sidewalls of said chamber, and means for rotating said eccentric to thereby reciprocate said shuttle block, said eccentric closing said inlet opening and thereafter pressurizing the fluid within the pumping chamber until said outlet opening is aligned with said outlet port.
 2. A rotary pump as set forth in claim 1 wherein said casing has parallel top and bottom walls and a pair of parallel sidewalls, said inlet port being positioned in the top wall and the outlet port being positioned in one of the sidewalls, a second inlet port positioned in aligned relationship with the first named inlet port and located in said bottom wall, and a second outlet port positioned in the other sidewall and aligned with the first named outlet port, said pumping chamber having a second inlet opening aligned with the first named inlet opening and having a second outlet opening aligned with the first named outlet opening, rotation of said eccentric alternately pressurizing the fluid in opposite ends of the pressure chamber and reciprocation of said shuttle block alternately discharging the pressurized fluid through said first named and second outlet openings when the latter registers with first named and second outlet ports.
 3. A pump as set forth in claim 1 wherein the volume of the pumping chamber between one end thereof and the eccentric is a minimum when the outlet opening registers with the outlet port.
 4. A pump as set forth in claim 2 wherein the volumes between opposite ends of the pumping chamber and the eccentric are alternately at a minimum during reciprocation of said shuttle block in opposite directions. 